1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * BGRT boot graphic support
  4 * Authors: Matthew Garrett, Josh Triplett <josh@joshtriplett.org>
  5 * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
  6 * Copyright 2012 Intel Corporation
  7 */
  8
  9#include <linux/kernel.h>
 10#include <linux/init.h>
 11#include <linux/device.h>
 12#include <linux/sysfs.h>
 13#include <linux/efi-bgrt.h>
 14
 15static void *bgrt_image;
 16static struct kobject *bgrt_kobj;
 17
 18static ssize_t show_version(struct device *dev,
 19			    struct device_attribute *attr, char *buf)
 20{
 21	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.version);
 22}
 23static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
 24
 25static ssize_t show_status(struct device *dev,
 26			   struct device_attribute *attr, char *buf)
 27{
 28	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.status);
 29}
 30static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
 31
 32static ssize_t show_type(struct device *dev,
 33			 struct device_attribute *attr, char *buf)
 34{
 35	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_type);
 36}
 37static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
 38
 39static ssize_t show_xoffset(struct device *dev,
 40			    struct device_attribute *attr, char *buf)
 41{
 42	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_x);
 43}
 44static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
 45
 46static ssize_t show_yoffset(struct device *dev,
 47			    struct device_attribute *attr, char *buf)
 48{
 49	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_y);
 50}
 51static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
 52
 53static ssize_t image_read(struct file *file, struct kobject *kobj,
 54	       struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 55{
 56	memcpy(buf, attr->private + off, count);
 57	return count;
 58}
 59
 60static BIN_ATTR_RO(image, 0);	/* size gets filled in later */
 61
 62static struct attribute *bgrt_attributes[] = {
 63	&dev_attr_version.attr,
 64	&dev_attr_status.attr,
 65	&dev_attr_type.attr,
 66	&dev_attr_xoffset.attr,
 67	&dev_attr_yoffset.attr,
 68	NULL,
 69};
 70
 71static struct bin_attribute *bgrt_bin_attributes[] = {
 72	&bin_attr_image,
 73	NULL,
 74};
 75
 76static const struct attribute_group bgrt_attribute_group = {
 77	.attrs = bgrt_attributes,
 78	.bin_attrs = bgrt_bin_attributes,
 79};
 80
 81int __init acpi_parse_bgrt(struct acpi_table_header *table)
 82{
 83	efi_bgrt_init(table);
 84	return 0;
 85}
 86
 87static int __init bgrt_init(void)
 88{
 89	int ret;
 90
 91	if (!bgrt_tab.image_address)
 92		return -ENODEV;
 93
 94	bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
 95			      MEMREMAP_WB);
 96	if (!bgrt_image) {
 97		pr_notice("Ignoring BGRT: failed to map image memory\n");
 98		return -ENOMEM;
 99	}
100
101	bin_attr_image.private = bgrt_image;
102	bin_attr_image.size = bgrt_image_size;
103
104	bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
105	if (!bgrt_kobj) {
106		ret = -EINVAL;
107		goto out_memmap;
108	}
109
110	ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
111	if (ret)
112		goto out_kobject;
113
114	return 0;
115
116out_kobject:
117	kobject_put(bgrt_kobj);
118out_memmap:
119	memunmap(bgrt_image);
120	return ret;
121}
122device_initcall(bgrt_init);